For some time, it has been desirable to have available for various uses, including in ventilated seats and in industrial pallets, an economical single sheet member formed from resilient plastic which will support a body in spaced relation to a supporting structure, where the member is formed from a single sheet of plastic which is permanently deformed to produce spacing elements or protuberances which not only will space the upper surface of the member above the supporting structure but will resiliently rigidify the overall member to prevent excessive flexing or any undesirable amount of flexing in use.
In U.S. Pat. Nos. 3,162,487 and 3,162,488 of H. H. Trotman, a single sheet of plastic is deformed to produce spacing elements of protuberances in a ventilated seat cushion. In these patents, however, the sheet of plastic, although adequately performing the spacing function as part of the seat construction, requires additional stiffening members in order to assure that the seat will retain its shape.
U.S. Pat. No. 2,948,334 of Goldstein is another example of a prior art attempt to produce a ventilated seat cushion from a sheet of plastic where the product lacks the necessary combination of rigidity and resilience for a successful product.
In U.S. Pat. No. 3,940,183, a support panel for use as a ventilated body support mat is disclosed having a plurality of integral T-shaped elements arrayed in columns and rows in an attempt to attain the desired combination of rigidity and resilience. Here again the desideratum is not attained as is evidenced by the provision of supplemental stiffening means.
In the past, industrial pallets have been designed to be picked up by fork trucks thereby requiring relatively complex supporting structures. More recently the concept of a pallet which can be skidded onto a fork truck has been introduced. The body support member of the present invention constitutes an ideal structure for the latter method of handling palletized loads.
By an ingenious interrelationship of elongated protuberances formed by permanent deformation of a sheet of plastic material, the present invention supplies the deficiencies of the prior art. By using a sheet of plastic material which, when shaped in accordance with the present invention is resilient in the realm of the forces exerted by the weight of a human body, the formed sheet of plastic material of the present invention can be used as a member which is rigid enough to retain its shape while at the same time exhibiting a springy characteristic so as to act as a cushion between a human body and a supporting structure. This is especially the case where the sheet of plastic material is superposed on a cushion such as an automobile seat cushion to achieve ventilation between the person supported on the sheet of plastic material and the automobile seat. On the other hand, the body support member of the present invention can perform the functions of an industrial pallet where no cushioning action is desired but rather the desideratum is a flat supporting surface of sufficient rigidity to act as a skiddable base for a stack of industrial products, this being attained by utilizing a heavier gage of plastic sheet material with greater rigidity and strength.
Although from the foregoing and as description of the present invention proceeds, it will be apparent that the body support member of the present invention is applicable to fields other than seat cushions, the invention will be described in the seat cushion environment where the resilience of the thin sheet of plastic material, taken in conjunction with the configuration of the sheet, can be utilized to great advantage.